Conventionally, to fabricate an electronic package particularly for use in an electroluminecent driver with a coil assembly, an integrated circuit, a coil assembly, capacitors, resistors and other electronic components are first mounted on a wafer. The electronic components are then encapsulated by an encapsulating epoxy resin. After the epoxy resin is cured, the wafer is diced to individual packages. FIGS. 7a and 7b are a sectional and plan view of such a conventional electronic package.
Specifically, the electronic package includes a substrate 10. A coil assembly 12, an integrated circuit 14, capacitors 16 and resistors 18 are mounted on the substrate 10 and electrically connected to a wiring metal film 20 which is, in turn, disposed on the substrate 10. All the components are encapsulated by an encapsulating resin 19. The wiring metal film 20 is electrically connected to a terminal or via. The via includes a through-hole 22 defined in the substrate 10 and a conductive element 24 made of metal and disposed on the side wall of the through-hole 22.
There is a need to reduce the size of the electronic package and shield the electronic components from electromagnetic noise.
To provide an electromagnetic shield, the surface of the encapsulating resin may, for example, be coated with nickel and other metals, as disclosed in Japanese patent application publication No. 11-163583. To enhance such a shielding effect, the encapsulating resin may be made of resin containing ferrite particles and coated with a metallic layer, as disclosed in Japanese patent application publication No. 11-237860.
None of those techniques, however, meets the above need to reduce the size of the electronic package.
The electronic package is also subject to warping, for example, during being mounted on the substrate of a cell phone and heated to a high temperature within a reflow oven.
It is, therefore, an object of the present invention to provide an electronic package and a packaging method which can eliminate the foregoing problems.